Standing Solution Gas-Oil Ratio Calculator
Enter absolute pressure in psi, temperature in Fahrenheit, oil API gravity and gas specific gravity to estimate solution GOR in scf/STB with the simplified Standing form.
Enter absolute pressure in psi, temperature in Fahrenheit, oil API gravity and gas specific gravity to estimate solution GOR in scf/STB with the simplified Standing form.
Published by PetroCalcHub Team. Linked workflow tools and revision log.
Calculation context and source notes
Estimate solution gas-oil ratio in scf/STB using the simplified Standing expression implemented on this page: gas specific gravity multiplied by [(p/18) x 10^(0.0125 API - 0.00091 t)]^1.2048. Pressure, temperature and gravity must describe the same fluid condition.
Use this reference to reproduce the declared simplified Standing calculation, then compare it with measured PVT data or the linked full Standing versus Vasquez-Beggs workflow. Solution GOR describes dissolved gas per stock-tank barrel, not an arbitrary surface produced-gas/oil ratio.
Texas A&M reservoir-fluid notes: solution GOR, page A-43Solves for
R_s (SCF/STB)
Best next page
Formula, variables, and sourceWhich Standing equation is being evaluated?
The displayed formula retains the historical simplified denominator 18 and exponent 1.2048. Texas A&M's reservoir-fluid appendix shows the corresponding p/18 expression with the exponent printed as 1.204, and distinguishes below-bubble-point behavior from constant solution GOR above bubble point.
The linked comparison workflow uses (p/18.2 + 1.4) with exponent 1/0.83 instead. Those constants are part of the model, not display rounding. Select a formula deliberately before interpreting differences between calculators; this page does not silently substitute the workflow equation.
Reproduce the default solution-GOR result
At 2,500 psia, 180 F, 30 API and gas gravity 0.8, the decimal exponent is 0.0125 x 30 - 0.00091 x 180 = 0.2112. The simplified calculation returns 548.314278 scf/STB, or about 548.31 scf/STB.
Use that result as a reproducible arithmetic check only. When transferring Rs to an oil-FVF or viscosity calculation, preserve the sample identity, pressure, temperature and saturation condition rather than mixing unrelated defaults.
Compare compatible calculations
Standing vs Vasquez-Beggs PVT ComparisonRelated source-backed guides
Formula, variables, and default calculation
Reproducible default result
With the default values shown below, the calculation returns R_s = 548.314278 SCF/STB. Defaults demonstrate the implementation; they are not recommended field values.
0.8
2500
30
180
Input definitions
gamma_g
fractionGas Specific Gravity
p
psiPressure
API
APIOil API Gravity
t
°FTemperature
Output definitions
R_s
Solution Gas-Oil Ratio
gamma_g
Gas Specific Gravity
p
Pressure
API
Oil API Gravity
t
Temperature
Engineering use, assumptions, and limits
Use this reference to reproduce the declared simplified Standing calculation, then compare it with measured PVT data or the linked full Standing versus Vasquez-Beggs workflow. Solution GOR describes dissolved gas per stock-tank barrel, not an arbitrary surface produced-gas/oil ratio.
Assumptions
- Pressure and temperature describe a saturated-oil condition consistent with the selected solution-GOR model.
- Gas specific gravity and oil API gravity describe the same fluid sample and use the correlation's reference basis.
Limitations
- The calculator does not accept bubble-point pressure or hold Rs constant above it; the user must establish the applicable pressure regime.
- The simplified p/18 form is not numerically identical to the full Standing inversion used in the comparison workflow, and neither is a laboratory measurement.
Common mistakes
- Entering gauge pressure where absolute pressure is required, or Rankine where Fahrenheit is required.
- Comparing two Standing results without checking the pressure offset, denominator and exponent used by each implementation.
- Extrapolating a saturated Rs curve above the measured bubble point without an undersaturated-fluid model.
Frequently asked questions
What inputs does the Solution Gas-Oil Ratio - Standing Correlation calculator need?
The calculation uses Gas Specific Gravity (gamma_g), Pressure (p), Oil API Gravity (API), Temperature (t). Enter values on the units shown beside each field.
What result does this calculator return?
The primary result is solution gas-oil ratio in SCF/STB. The formula section shows the declared relationship, variables, and a reproducible default calculation.
What should I check before using the result?
Confirm the unit basis, source applicability, and input quality. The calculator does not accept bubble-point pressure or hold Rs constant above it; the user must establish the applicable pressure regime. Entering gauge pressure where absolute pressure is required, or Rankine where Fahrenheit is required.
Source and record status
Source metadata identifies the relationship implemented by the calculator. Check the cited edition, unit basis, and scope against the engineering case before operational use.
Guo, B., Lyons, W.C. and Ghalambor, A. 2007. Petroleum Production Engineering: A Computer-Assisted Approach, Page 2/20.
Open source reference